Abstract: One embodiment of a tricycle (20) having a spine frame (22), supported by a rear wheel (34) and a pair of steerable front wheels (36), and supporting a recumbent seat (42) pivotably attached at its rear. A pedal boom (44) extends forwardly of the spine (26) and supports a pedal crank assembly (46). The front wheels each support a lateral arm (28) with the front wheel pivotably attached at the distal end and an angular projection (80) attached at the proximal end. A pivot (78) connects each angular projection to the spine, allowing the lateral arms and attached front wheels to fold to a stowed position alongside the spine. Another pivot (84) connects the boom to the spine, allowing the boom fold back to a stowed position against the spine. In the travel position, clamping means arrest the angular projections, and can arrest the boom and seat. The tricycle is collapsible to several levels of compactness. Other embodiments are described and shown.

Abstract: An improved power transfer mechanism for use on a human-powered machine, adapted to be drivingly connected to a power take-off device of said machines, includes: a housing adapted in use, to be disposed within a frame of said human-powered machine; at least one crankshaft adapted to be disposed within said housing; respective left-side and right-side crank arms each adapted to be drivingly associated with an end of said at least one crankshaft; and drive transfer means adapted to co-operate with said at least one crankshaft and each associated crank arm, the arrangement being such that a first member of the group comprising and left-side and right-side crank arms and said power take-off device is adapted to be attached to said at least one crankshaft, such that each of the second and third of said members is adapted to be rotatable relative to said first of said members, and each other, only to a limited and controlled degree, whilst not be movable axially or in a longitudinal direction relative to said at le

Abstract: The present disclosure provides a kit and method for modifying a bicycle comprising attaching a platform to both sides of the bottom bracket crank spindle in place of a crank set and chain. The platforms include internal spindle slots adapted to crank spindle shape through which a screw or other fastener may be used to temporarily attach the platform to the bottom bracket crank spindle.

Abstract: An extended crank system for a bicycle or similar crank driven system has frame with a bottom bracket and a pair of cranks operatively connected to opposite ends of the bottom bracket. A chain ring is operatively connected to one of the cranks. A crank hub is rotatably connected to each of the cranks and extends away from and is substantially parallel to the bottom bracket. A pair of crank extensions is connected to the crank hub, and a pair of crank extension hubs is connected to the pair of crank extensions. Additionally, a pair of crank followers is pivotably connected to opposite ends of the crank extension hubs at respective first ends of the crank followers, as well as pivotably connected to opposite ends of a top bracket mounted to the frame above the chain ring and behind the seat post, at respective second ends of the crank followers.

Abstract: The present invention consists of a human-powered, wheeled vehicle, having: a) two front wheels, each of the two front wheels pivotally coupled to a frame by a pivoting mount; b) one or more rear wheels, one or more of the rear wheels coupled to a drive mechanism and operative to provide a driving force for the vehicle; and c) a steering mechanism coupled to the front wheels, the steering mechanism including a handle for steering control by a driver of the vehicle, a first linkage connecting the handle to a first one of the pivoting mounts and a second linkage connecting the first one of the pivoting mounts to a second one of the pivoting mounts.

Abstract: A two wheel steering bicycle with two steering controls and rider positioned facing an angle greater than zero and less than ninety degrees with respect to the direction of motion. A frame member connects the rear head tube to the front head tube. The rear fork can rotate within the rear head tube. A rear steering handle is connected to the rear fork. The front fork can rotate within the front head tube. A front steering handle is connected to the front fork. A seat tube member attaches to the frame member. A bicycle saddle is attached to the seat tube member in such a way as to position the rider facing an angle greater than zero and less than ninety degrees with respect to the longitudinal axis of the frame member.

Abstract: A bicycle adaptable to different forms of cycling. The bicycle includes a frame modification of the location of the crankshaft unit in the frame. The bicycle frame includes a crankset box forming a main housing. The crankset box is positioned at the junction of first and second rods. A detachable body member is mounted in the main housing, and includes a special housing that may be centered or off center relative to the base of the detachable body member.

Abstract: A drive device, which has a drive shaft mounted in such a way as to rotate about an axis, two driving cranks which are connected to the drive shaft in an angularly rigid manner in relation to the axis in the peripheral direction, and an output element which is connected to the drive shaft and transmits torque between the drive shaft and a load element. To enable the measurement of the torque transmitted by the shaft as easily and economically as possible, the drive device has at least one magnetostrictive sensor which is connected to the drive shaft in a fixed manner and axially arranged between a driving crank and the output element.

Abstract: Strain gauges are mounted on each crank arm of the bicycle and provide a measure of the torque applied to each crank arm. In a preferred embodiment, strain gauges are mounted on opposite edges of each crank arm, which includes a self-contained power, electrical circuitry, and a wireless transmitter for transmitting the strain measurement information to a main controller. The main controller includes a wireless transceiver for transmitting and receiving data from both the left and right crank arms and external devices. Memory is also included for storing such data for subsequent analysis to determine the individual leg performance of a cyclist during a race or training session.

Abstract: A method and apparatus for training a beginning cyclist to ride a bicycle. One embodiment includes providing a bicycle with detachable pedals and at least a portion of the crank arms, and attaching guard shields on the remaining portions of the crank arms.

Abstract: Improvement in the design of variable original radius chainrings for coupling to conventional bicycle cranks in order to apply traction, which primarily consists of its being provided with a plurality of possible anchorages to the crank, so that the user may adjust the relative position between the crank and the major radius of the chainring, and thus optimize the biomechanics of his own pedalling; furthermore, other design parameters are offered to endow this non-circular pedalling with leg speeds optimized within the limitation of pedalling with cranks at 180 degrees and therefore with a dead spot.

Abstract: An economically operated low cost wheeled vehicle that accommodates a single driver occupant is propelled by power provided by a controllable combination of pedaling action of the driver, an internal combustion engine and an electric motor. The vehicle is elongated upon a center axis between a front extremity and a rear extremity having a single, axially centered wheel that drives the vehicle.

Abstract: A cycle with a mechanical advantage drive and leaning steering system comprises a frame with at least one wheel rotationally attached to the frame. A drive rim is attached to the wheel adjacent to the outer circumference of the wheel. A pulley is rotationally attached to the frame. A belt is trained around and engages both the pulley and the drive rim. Because the belt is positioned at the outer circumference of the wheel a mechanical advantage is created that significantly reduces the amount of force required on the belt to propel the cycle. The cycle may be steered via the rotation of the rider's body on a seat. This rotation translates to rotation of a front portion of the frame with respect to the a rear portion of the frame about a pivoting interface portion, thereby causing the cycle to turn.

Abstract: A bicycle crank assembly is configured to simplify the work required to adjust the bearing play by the crank assembly when the crank assembly is mounted. The bicycle crank assembly has a left crank that is mounted on a crank axle of the bicycle, and is provided with a crank body and an adjustment member. The crank body includes a crank axle mounting part non-rotatably mounting to one end of the crank axle, an arm part extending from the crank axle mounting part, a pedal mounting part for mounting the pedal and provided at the tip of the arm part, and a male screw part formed on the crank axle mounting part. The adjustment member includes a tubular part having a female screw part into which the male screw part is screwed, and a contact part formed at one end of the tubular part and capable of contacting the bearing supporting the crank axle.

Abstract: The present invention is related to a manpower driven device being able to do particular bidirectional pedaling to provide constant directional output for driving the loading wheel train, wherein its pedaling direction is selected by the rider according to his/her operating statuses of the muscles and joints, or the same directional outputs of different speed ratios is made further through the different driving directional inputs.

Abstract: A bicycle is provided on which a person can efficiently ride in a comfortable posture along a slope and effectively utilize the strength of the legs while pedaling along a level road.

Abstract: A powered, directionally steerable trailer jack that can be used to elevate and lower a trailer tongue and having a caster wheel assembly affixed to a lower end of the jack. The caster wheel assembly includes a shroud having the wheels' axle journaled for rotation at a lower end thereof along with a pair of shafts also journaled for rotation in the shroud and oriented parallel to the axle. A chain and sprocket arrangement provides a low-speed, high torque transmission between one of the shafts and the axle and a high-speed, low torque transmission between the other of the shafts and the axle. The trailer jack assembly can be tilted out of its vertical disposition to provide adequate clearance when the trailer is being pulled over uneven road surfaces. The power for driving the wheels may be provided manually by means of a crank for turning one or the other of the shafts or by an electric motor coupled one of the shafts.

Abstract: The invention relates to an assembly (1) of bicycle components in mutual rotation, like for example a bottom bracket assembly. The assembly of the present invention comprises a support element (15), a rotary element (5) rotatably coupled with the support element (15) and at least one bearing (20) arranged between the support element (15) and the rotary element (5). The bearing (20) comprises at least one bearing element (30, 40) firmly coupled with one from the support element (15) and the rotary element (5). The bearing element (30, 40) and the element (5, 15) with which it is firmly associated have, at respective mutually coupled interface surfaces (36, 38, 42, 44),a standard reduction potential difference lower than or equal to 0.3 V, in absolute value.

Abstract: The present invention relates to a unique convertible ride-on vehicle. The ride-on vehicle of the present invention includes at least one font wheel, at least two rear wheels mounted on a rear axle, a frame supported by the at least one front wheel and the at least two rear wheels, a torque input mechanism, a torque transfer mechanism for transferring torque from the torque input mechanism to the rear wheels. The ride-on vehicle of the present invention is convertible between a first, tricycle configuration in which the rear wheels are spaced apart on the rear axle and a second, bicycle configuration in which the rear wheels are in close proximity to each other. Finally, the present application discloses a clean, simple method and apparatus for adjusting the tension of a chain or belt utilized to drive a ride-on vehicle.

Abstract: A muscle-powered machine has a frame, a drive wheel rotatably mounted on the frame and rotatable in a plane defining a normal straight-ahead travel direction, and a drive pedal engageable with a foot of a user of the machine and having one end pivoted on the frame forward of the user's foot. The pedal is pivotal through an acute angle on the frame between an upper position and a lower position with the pedal extending at an angle of 90° ±10° to a lower leg of the foot on the pedal. A quotient of the maximum vertical travel of the pedal measured perpendicular to the pedal in its lower end position and the sine of the angle is greater than the length of the pedal measured radially of its pivot. A drive connected between the pedal and the drive wheel converts oscillation of the pedal between its end positions into rotation of the wheel.

Abstract: A crank is provided with a crank axle connecting portion for connecting a crank axle thereto, a pedal connecting portion for connecting a pedal thereto, and a main crank portion positioned between the crank axle connecting portion and the pedal connecting portion. A first insert member is arranged in the crank axle connecting portion, and has an axle attaching part having a crank axle connecting hole and an extended part extending from the axle attaching part toward the pedal connecting portion so as to following along the main crank portion. The crank axle further includes a shell member made of a fiber-reinforced resin that at least partially covers an outside facing surface of the first insert member.

Abstract: A combination vehicle frame includes a base frame unit formed of a plurality of frame bars detachably connected to one another. One of the frame bars is provided with a head having intersected first through hole and second through hole. A rear wheel frame unit is detachably connected to the base frame unit remote from the head. A front wheel frame unit is selectively inserted through one of the first through hole and second through hole of the base frame unit.

Abstract: Wheeled riding vehicles, including tricycles, with extremely thin stowed profiles are provided, which in one embodiment, include movable, collapsible tires/wheel axle assemblies, as well as folding frame parts and a unique handle that is removable and stowable within the vehicle frame when not used. The riding vehicle hangs totally flat on the wall, or fits in car trunks easily. One version is pedal powered, and a second embodiment provides for an integrated propulsion linkage providing for battery or motor power to the rear most wheels when they are moved into their operative position. The rear tire wheel assemblies also may be stowed and folded compactly inside a rear storage compartment with a lid.

Abstract: The present invention relates to a bicycle drive unit that moves forward and backward and idles upon clockwise and counterclockwise pedaling, comprising: a drive shaft having one end located in an inner bearings of an internal bearing housing integrally formed with a rotary plate and the other end fixed to a clockwise one-way clutch and the inner wheel of a counterclockwise one-way clutch by means of a sunk key; a counterclockwise one-way clutch having a central gear press-fitted on its outer wheel; a ring gear engaged with the turnabout gear; a gear flange connected to a ring gear by means of a locking screw; a bearing housing of a dual structure consisting of an outer bearing housing having outer bearings; a brace attached to the outer circumference of the outer bearing housing by means of the locking screw; a detent pin unit for curving the internal bearing housing and the rotary plate; and a bicycle backward movement control unit having a hand lever and a detent latch.

Abstract: A crank for a bicycle, excellent in production efficiency, excellent in fatigue durability and rigidly, and light in weight. The crank has an outer shell made of a fiber-reinforced plastic, a first insert member configured and arranged to introduce a load from a pedal shaft, and a second insert member coupled to a bracket spindle and configured and arranged to transmit a load to a sprocket. The outer shell comprises at least two fiber-reinforced plastic members at least a part of each of which is molded in advance.

Abstract: A pedalling method and device for a user in standing position. The device includes a drive shaft whereof the rotation about its axis is coupled with the rotation of two right and left pedals. The pedals are mutually assembled via a plurality of cranks, connecting rods, and pivots such that: the pedals can travel freely along a circular path, for a constant rotational speed of the shaft, the speeds of the pedals are recurrent at equal time intervals but out of phase, minimal at lower dead center, maximal at upper dead center, and when the pedals are simultaneously at a common height lower than that of the center of the trajectory, the speeds of the pedals are equal. The vertical oscillation of the center of gravity of a user in standing position is reduced compared to a conventional pedal assembly.

Abstract: Embodiments of the present invention comprise assemblies for converting an upright-style bicycle into a recumbent bicycle. Additionally embodiments comprising the converted bicycle are also described.

Abstract: A transmission mechanism is used in a bicycle having a frame. The transmission mechanism includes a quick assembly device including a central shaft, threaded collars, and a clip bracket, which is adapted to mount to a lower frame portion of the bicycle frame and a multi-mode mechanism, which is supported and fixed by the quick assembly device to provide the bicycle with multiple modes of pedaling.

Abstract: A bottom bracket assembly for a bicycle is provided. The bottom bracket assembly may comprise a left bearing, bottom bracket shell and a right bearing. The bottom bracket shell may be threadless and have beveled surfaces for mounting the left and right bearings onto the bottom bracket assembly. A spindle is inserted through the bottom bracket shell. Thereafter, the left and right bearings are preloaded to align the central axis of the spindle to the crankarm rotating axis such that the spindle or left and right crankarms do not wobble and yet do not bind when rotated.

Abstract: A method for electronically servo-assisting a bicycle gearshift, including the steps of: a) driving an actuator of a bicycle gearshift to displace a chain of the gearshift in an axial direction with respect to a gearshift group comprising at least two sprockets; b) receiving information on the desired alignment between the chain and a predetermined sprocket of the gearshift group; and c) setting a biunique correspondence between the physical position of the actuator at step b) and a logic value associated with the gear ratio relative to the predetermined sprocket.

Abstract: A bicycle frame assembly including a down tube and a monolithic down tube support. The down tube support preferably defines a pocket configured to receive an end portion of the down tube such that the tube support overlaps at least a portion of a side surface of the end portion of the down tube. In one embodiment, a weld bead joins both of the tube support and the down tube. Preferably, the down tube support also defines an opening configured to receive and support a pedal crank assembly relative to the bicycle frame. Furthermore, preferably the down tube support also includes a pivot mount portion configured to rotatably support a sub-frame of the frame assembly or a rear shock absorber.

Abstract: The present invention relates to a bicycle drive unit of multiple pedaling modes, comprising a drive shaft on one side having a counterclockwise one-way clutch and a clockwise one-way clutch coupled thereto by means of sunk keys and the drive shaft is engaged with a ring gear having an outer circumference attached to a chain sprocket; a plurality of hollow turnabout gears engaged with the central gear of the drive shaft; a drive shaft on the other side having one side rotatably inserted into an inner bearing housing that is integrally formed with the rotary plate and the other side coupled to the inner wheels of the clockwise one-way clutch and the counterclockwise one-way clutch by means of the sunk keys and a plurality of turnabout gears, a two-way turnabout gear and a hollow turnabout gear.

Abstract: A foldable bicycle includes a head strut, a seat strut, and first and second bracing struts pivotally mounted to one another about four pivot axes such that lifting of a pivot joint of the first and second bracing struts towards the head strut results in turning of the first and second bracing struts to bring the bicycle into a folded position, where front and rear wheels are closer to each other and are held in tandem. A locking member is disposed to releasably lock the second bracing strut from turning relative to the first bracing strut when the bicycle is in a position of use.

Abstract: A crank apparatus includes a driven member rotatably mounted to a machine, and a crank arm attached at an inner end thereof to the driven member at a rotational axis of the driven member such that the driven member and crank arm rotate together. An axle is slidably mounted to the crank arm such that the axle is maintained substantially parallel to the rotational axis of the driven member as it slides from an inner point on the crank arm, to an outer point on the crank arm, and a bias element is arranged to exert a force on the axle toward the rotational axis of the driven member.

Abstract: An operator-propelled, four-wheel vehicle uses a treadmill to drive two rear wheels through a bicycle type derailleur and sprocket gear shifter which provides gear changing capability. The front wheels, each of which have disk brakes, are steered by an automotive type steering apparatus. A vertical extension from the steering mechanism at the front of the vehicle mounts a horizontal steering bar to provide steering control. The steering bar also mounts control grips and cables for the front disk brakes and clutch assembly, as well as the gear shifter. An automatic breaking system ensures that an unmanned vehicle will remain in place.

Abstract: A cycle that has two fixed frame arms extending down on each side of the head tube axis, and a steering arm rotatably mounted in the head tube extends down between the frame arms and has a laterally off-set lower portion. A mounting member is fixed to the lower end of the steering arm and has a hollow cylindrical wheel support section which carries the inner portion of a bearing or bearings for the front wheel, allowing this wheel to rotate while being steerable by the steering arm. A fixed pedal axle extends freely through the hollow wheel support section and is rotatably supported by lower ends of the frame arms, this axle being connected by drive means to one of the cycle's front or rear wheels. Parts of the mounting member have an enlarged interior space relative to that in the wheel support section to accommodate steering movement of the mounting means relative to the pedal axle.

Abstract: A control apparatus for an electrically operated bicycle transmission comprises a power supply sensor and a control unit operatively coupled to the power supply sensor. The power supply sensor senses a power characteristic of a power supply, and the control unit provides a signal to operate the bicycle transmission when the power characteristic falls below a predetermined value. Alternatively, the control apparatus comprises a running condition time sensor and a control unit operatively coupled to the running condition time sensor. The running condition time sensor senses a time interval of a running condition of a bicycle, and the control unit provides a signal to operate the bicycle transmission to a predetermined gear ratio when the time interval of the running condition passes a selected value.

Abstract: The invention relates with the omni-directional toy vehicle that can move in all directions of forward, backward, rotational, left and right movement by driving manually the omni-directional wheels installed at the vehicle and combining their rotational directions. The vehicle characterized by comprising a frame composing the body of the vehicle, at least three rotating axles which are installed at the lower part of the frame with a rotatable mechanism, at least three omni-directional wheels which are connected to the axles, at least three driving element which are connected to the axles and drive the omni-directional wheels and a seat located at the upper part of the frame. The vehicle can be driven and steered simultaneously by means of driving combinations of each omni-directional wheel without any additional steering element and make an operator be interested in the manual operation of omni-directional wheels.

Abstract: A crank is provided with a crank axle connecting portion for connecting a crank axle thereto, a pedal connecting portion for connecting a pedal thereto, and a main crank portion positioned between the crank axle connecting portion and the pedal connecting portion. A first insert member is arranged in the crank axle connecting portion, and has an axle attaching part having a crank axle connecting hole and an extended part extending from the axle attaching part toward the pedal connecting portion so as to following along the main crank portion. The crank axle further includes a shell member made of a fiber-reinforced resin that at least partially covers an outside facing surface of the first insert member.

Abstract: A pedal-operated crank drive assembly for a bicycle includes a crank axle, a crankset rotatably disposed on the crank axle and including a tubular mount portion which surrounds the crank axle, a crankarm having a drive delivering head which is coupled to the crank axle to be rotated therewith and which has a plurality of angularly displaced recesses, a plurality of pawls disposed respectively in the recesses to be movable between driving and idle positions, and an annular toothed member disposed on the tubular mount portion to couple with the pawls to form a uni-directional mechanism. A plurality of biasing members are disposed to bias a respective one of the pawls to the driving position. A flexible annular shield member is disposed to prevent entry of extraneous dirt into the drive delivering head.

Abstract: A bicycle having a frame with a single steering arm rotatably mounted in the frame and extending downwardly away from the frame. A wheel support is provided at the end of the arm and a front wheel is rotatably mounted on the wheel support with a single bearing. The bicycle can have a pair of frame arms extending down from the frame with the steering arm between the frame arms and adjacent one of the arms so the front wheel is located between the arms. The frame arms carry pedal means with the axle of the pedal means passing freely through the hub of the front wheel and through the wheel support without connecting to them. Drive means are provided between the pedal axle and the front wheel for propelling the bicycle.

Abstract: A bicycle control apparatus comprises a mounting member structured to be attached to a bicycle, a control unit structured to be mounted to the mounting member and a battery unit structured to be detachably mounted to the control unit above the control unit.

Abstract: A tricycle crank structure comprises a wheel axle, a pair of cranks and a pair of pedals. The wheel axle is provided with a pair of non-circular sectional holes at respective ends. The inner wall of each hole is provided with a recess. Each crank has one end pivotally connected to the pedal and another end provided with a connecting section. The connecting section is provided with a tenon to engage with the recess of the hole for quick mounting and dismounting. Each hole may be provided with a pair of through holes, and each crank is provided with an elastic clip for connection.

Abstract: The present invention relates to an auxiliary power unit starting apparatus for an electric bicycle, which can convert the rider's pedaling force into mechanical displacement at the time the bicycle is being pedaled, and then the mechanical displacement can start the auxiliary power unit of the electric bicycle. The device of the present invention has simple structure and small size, and it can be easily manufactured and assembled.

Abstract: A method for electronically servo-assisting a bicycle gearshift, including the steps of: a) driving an actuator of a bicycle gearshift to displace a chain of the gearshift in an axial direction with respect to a gearshift group comprising at least two sprockets; b) receiving information on the desired alignment between the chain and a predetermined sprocket of the gearshift group; and c) setting a biunique correspondence between the physical position of the actuator at step b) and a logic value associated with the gear ratio relative to the predetermined sprocket.

Abstract: A scooter includes a main body, a rear wheel mounted on a rear end of the main body, and an operation mechanism mounted on the main body and connected to the rear wheel to move the rear wheel. When in use, the rider steps on the two pedals to move the scooter forward manually. Alternatively, the scooter is moved forward automatically by operation of the motor. Thus, the scooter is operated manually by the user's feet or operated automatically by an electric power. In addition, the operation mechanism is detachably mounted on the main body, thereby facilitating the rider using and folding the scooter.

Abstract: A vehicle transmission includes a plurality of driven gears comprising a series of concentrically spaced ring gears. Each ring gear of the plurality of driven ring gears has an inner diametrical surface and an outer diametrical surface. Each outer diametrical surface is configured to slidingly engage the inner diametrical surface of an adjacent ring gear. The vehicle transmission further includes a biasing means for biasing each ring gear away from a driven shaft and a selective engagement means for selectively engaging one ring gear of the plurality of ring gears with the driven shaft.

Abstract: A method for electronically servo-assisting a bicycle gearshift to allow compensation for misalignments between the chain of a bicycle gearshift and one or more sprockets of the gearshift, the method including the steps of: driving an actuator of a bicycle gearshift to displace a chain of the gearshift in a chosen direction with respect to a gearshift group comprising at least two sprockets; receiving information on the desired alignment between the chain and a predetermined sprocket of the gearshift group; and setting an adjustment variable, of a logic value associated with the gear ratio relative to the predetermined sprocket, to a value corresponding to the displacement carried out in the step of driving the actuator.

Abstract: A control apparatus for an electrically operated bicycle transmission comprises a power supply sensor and a control unit operatively coupled to the power supply sensor. The power supply sensor senses a power characteristic of a power supply, and the control unit provides a signal to operate the bicycle transmission when the power characteristic falls below a predetermined value. Alternatively, the control apparatus comprises a running condition time sensor and a control unit operatively coupled to the running condition time sensor. The running condition time sensor senses a time interval of a running condition of a bicycle, and the control unit provides a signal to operate the bicycle transmission to a predetermined gear ratio when the time interval of the running condition passes a selected value.

Abstract: A continuously variable transmission for bicycles having a transmission mechanism including a plurality of link units for converting rotary motion of an input shaft rotated by a pedal-operated crankshaft into swinging motion, and a one-way clutch for converting the swinging motion into rotary motion of an output shaft. The link units have drive links pivotally mounted on an eccentric ring which rotates in unison with the input shaft. The continuously variable transmission is disposed between a front wheel and a rear wheel of a bicycle in the longitudinal direction thereof and disposed either upwardly of a hypothetical plane which contains the axes of rotation of the front wheel and the rear wheel or upwardly of a position below and near the hypothetical plane. The transmission so configured provides better bicycle maneuverability, lower cost, while suffering almost no danger of contacting the ground.